On Fri, 6 Sep 2024, at 03:01, Mike Schinkel wrote: >> Block-scoping doesn't have to allow shadowing of names, > > How exactly would that work? Are you suggesting to restrict the use of > variable names to one per function but still allow for block scoping?
Yes. That's how C# works, for example - variables are scoped to the block where they're declared, but each name declared must be unique, not shadowing one that's currently in scope. > Shadowing is not a feature that is added, it is the result > of block scoping, AFAIK. Shadowing is absolutely a feature that has to be implemented: the compiler has to store some "backup" of the old name binding, so that it can be "restored" when the shadowing variable goes out of scope. Without shadowing, it's instead about tracking the "lifetime" of the variable, and refusing references to it outside of the block where it's "live". I'm sure the implementation of both versions varies wildly. > It is ironic you say we should make sure it's possible before we > discuss if we want it. I know I have heard the opposite many times on > this list — make sure we even want it before we worry about how to > implement — although I cannot say for sure that it was ever you that > said that. You're right, there is some value in letting people know that a feature would be popular if implemented. I'm just aware that threads like this can quickly grow into rambling discussions of wild ideas with little grounding in what's possible, or back-and-forth debates between two people about something completely hypothetical. When that happens, those with the experience to actually implement big new features tend to tune out. I will now try to practice what I preach, and not post further in this thread unless it moves onto something more concrete. Regards, -- Rowan Tommins [IMSoP]
